Generally, since a wireless communication system does not use a cable, there is no installation limitation in an aspect of geopolitics. Therefore, since extension or change of a line is not required even when a location of a terminal is changed or a terminal is added/deleted, manpower and economic costs can be remarkably reduced in comparison with wired communication. Accordingly, activities for realizing wireless communication environments using light (e.g., an infrared) instead of wired communication are under development.
Under this circumstance, a television apparatus allowing television viewing using a related art wired cable is also adapted to allow television viewing wirelessly. This wireless television system will be described with reference to FIGS. 1 and 2.
FIG. 1 is a schematic view illustrating a general wireless television system, and FIG. 2 is a circuit diagram illustrating a light-emitting unit provided to a related art wireless television system.
Referring to FIGS. 1 and 2, the wireless television system 10 can include a wireless transmitter 11, a wireless television 12, and a remote controller 13. The wireless transmitter 11 transmits video signals input from a broadcast signal input port, a digital versatile disk (DVD)/video cassette recorder (VCR) signal input port, or an S-video signal input port to the wireless television 12. The wireless television 12 receives video signals from the wireless transmitter 11 and displays an image corresponding to the video signals. Also, the remote controller 13 is a means for inputting a user's instruction.
The wireless transmitter 11 and the wireless television can include a light-emitting unit for displaying a power state and a signal transmission/reception state. The light-emission can include light-emitting devices (LEDs) emitting light when powers of the wireless transmitter 11 and the wireless television 12 are turned on.
The light-emitting unit provided to the wireless transmitter 11 of the wireless television system 10 will be described with reference to FIG. 2.
Referring to FIG. 2, the light-emitting unit provided to the wireless transmitter 11 can include at least one LED. A predetermined drive power Vcc is applied to one electrode of the LED. Also, a ground voltage can be applied to the other electrode of the LED. Therefore, when power of the wireless transmitter 11 is an on-state, the drive power Vcc is applied to the light-emitting unit, and a current path is formed by the drive power Vcc, the LED, and the ground voltage, so that the light-emitting unit emits light.
However, the LED installed in the wireless transmitter 11 continues to maintain a light-emitting state even when power of the wireless television 12 is set to an off-state and a user does not watch the television 12. That is, the LED provided to the wireless transmitter 11 keeps emitting light as far as power is constantly supplied to the wireless transmitter itself even when the user does not watch the television. In this case, power is unnecessarily consumed by the LED, and dazzling is generated to the user at night, which causes inconvenience.
Further, this problem becomes serious even more when the number of LEDs in use increases for easy checking of the LEDs by a user and elegant appearance.